United States
Environmental Protection
Agency
Industrial Environmental Research  ;
Laboratory                     ~
Cincinnati OH 45268

Research and Development
EPA-600/S2-84-111   Sept. 1984
Project Summary
Wastes from Manufacture  of
Dyes  and  Pigments

David C. Bomberger, Julia E. Gwinn, and Robert L. Boughton
  A preliminary study of the manufac-
ture of dyes and pigments was con-
ducted to determine if process waste
streams might contain hazardous mate-
rial. The study first identifies the dyes
and pigments that belong to the major
segments of the industry, the amounts
produced,  and the  known  U.S. pro-
ducers. The chemistry of these dyes and
pigments is discussed  as well as the
overall production process and waste
treatment practices. Waste streams that
could contain hazardous material are
identified and companies that produce
representative dyes and pigments are
recommended for a  sampling program
to confirm the composition and amounts
of these waste streams.
  This Project Summary was developed
by EPA'*Industrial Environmental Re-
search Laboratory, Cincinnati, OH, to
announce key findings of the research
project that Is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).

Introduction
  The Resource Conservation and Recov-
ery Act (RCRA) requires that  hazardous
solid wastes produced by manufacturing
operations be identified and disposed in a
manner that limits the release of hazard-
ous materials  to the environment. To
date, many specific waste streams from
manufacturing processes have been listed
in regulations as being hazardous be-
cause of their chemical composition. The
objective of this preliminary study is to
help determine if wastes produced by the
manufacture of dyes and pigments in the
United States  might require listing  as
hazardous materials. An analysis of both
the chemistry and the physical processing
involved in dye and pigment manufactur-
ing will be used to identify all wastes that
may contain significant chemical hazards.
An analysis of the industry will be used to
determine specific manufacturers where
the candidate wastes are produced. This
information will help the U.S.  Environ-
mental Protection Agency, Office of Solid
Wastes, to design a sampling and analysis
program to confirm or disprove the pre-
sence  of  hazardous materials in  the
candidate wastes and thereby develop a
basis for listing dye and pigment manu-
facturing wastes under RCRA. This report
summarizes  the content of nine reports
covering the following dye  and pigment
classes:

Volume I:  Azo Dyes and Pigments (Ben-
  zidine and Its Congeners)
Volume 2: Azo Dyes and Pigments (Ex-
  cluding Benzidine and Its Congeners)
Volume 3: Stilbene Dyes and Fluorescent
  Brightening Agents
Volume 4: Anthraquinone Dyes and Pig-
  ments
Volume 5: Diphenylmethane and Triaryl-
  methane Dyes and Pigments
Volume 6: Methine and Polymethine Dyes
  and Pigments
Volume 7: Xanthene Dyes and Pigments
Volume 8:  Phthalocyanine Dyes  and
  Pigments
Volume 9: Sulfur Dyes

Discussion
  Amongthe commonly recognized struc-
tural classes of dyes and pigments, the
most important commercially in the Unit-
ed States are the azo dyes and pigments.
The 1978 U.S. production of azo dyes and
pigments was approxi mately 41,000 met-

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ric tons or about 35% of all U.S. dye and
pigment  production.  These dyes  and
pigments are characterized by the pres-
ence of one or more azo groups—(-N=N-)
in the molecule. Consequently, the class
can be divided into subclasses (monoazo,
disazo, trisazo, tetrakisazo, and polyazo).
A special subclass consists of azoic com-
pounds, namely, azoic coupling compo-
nents, azoic compositions,  and azoic
diazo components, that are reacted on the
fiber to produce azo dyes. The azo dyes
and pigments class can also be divided
into  groups of dyes and pigments  pro-
duced from one  common,  structurally
related group of starting materials.  One
such group of starting  materials consists
of those substituted  biphenyls having
amine groups in both para positions (i.e.,
benzidine and related compounds having
additional substituents in the two rings).
Theoretically, this  group can include a
very large  number of compounds, but
commercially significant dyes are  pro-
duced from only a limited number of com-
pounds.
  The stilbene dyes share in common the
structural constituent 2,2'-stilbenedisul-
fonic  acid.  However, the chromophoric
system of the stilbene dyes is due to the
presence of an azo or azoxy group. Even
though the stilbene dyes are a  subdivision
of the azo  class, they are treated  as a
separate class because they are not
prepared by the classical azo coupling
reaction. Many fluorescent optical bright-
eners are also based  on  stilbene deriv-
atives and these  are included in the
Colour Index (The Society of Dyers and
Colourists,  1980) with the stilbene dyes.
  According to the U.S. Tariff Commis-
sion (1974), the U.S. commercial  pro-
duction of stilbene dyes and brighteners
for 1972 was 14,000 metric tons.  This
represented 12% of the total  reported
U.S.  commercial  dye  production  of
120,000 metric tons for that year. The
stilbene dyes and fluorescent  brightening
agents  represented the third  largest
structural class of dyes  based on  U.S.
commercial production volume. Approx-
imately two-thirds of  the stilbene dyes
and  brighteners production  was  attrib-
utable to the fluorescent brightening
agents. Data on U.S. production of dyes
by structural class have not been reported
si nee 1972; therefore, it was not possible
to determine from public sources whether
the relative importance and total produc-
tion of stilbene dyes and brighteners has
changed.
  In 1972, production of 21,200  metric
tons  for all  anthraquinone dyes  was
reported to the U.S. Tariff Commission
(1974). This represented 18% of the total
reported dye production. Anthraquinone
dyes and pigments represented the sec-
ond largest structural class of dyes based
on U.S. production volume. An industry
contact indicated that during the last few
years  U.S. commercial  production  of
anthraquinone dyes has decreased signif-
icantly.
  The  diphenylmethane and  triarylme-
thane dyes and pigments are among the
oldest synthetic dyes. They  give dyeings
of extreme brightness and purity, but
their fastness properties, particularly  to
light, are quite poor. Despite their light
fugitiveness,  these dyes and pigments
are widely used because of their brilliant
shades, their extremely high tinctorial
values, and their  relative  low cost.  In
1972, production of 4000 metric tons for
all triarylmethane dyes (this figure  in-
cludes diphenylmethane dyes) was re-
ported to the U.S. Tariff  Commission
(1974). This represents 3.4% of the total
reported U.S. dye production of 120,000
metric tons for that year. Diphenylme-
thane and triarylmethane dyes and pig-
ments represented the fourth  largest
structural class of dyes based on U.S.
production volume. Data on U.S. produc-
tion  by structural  class have not been
reported since 1972; therefore, it is not
possible to determine from public sources
whether the relative importance and total
production of these dyes and pigments
have changed.
  In  1972, production of 2,500  metric
tons for all methine and polymethine dyes
was reported to the U.S. Tariff Commis-
sion  (1974). This represents  2% of the
reported  U.S. dye production. Methine
and  polymethine  dyes and pigments
represented the  fifth  largest structural
class of dyes based on U.S. production
volume.  Data on U.S. production   by
structural class has not been reported
since 1972, so it is not possible to deter-
mine  from public sources  whether the
relative importance or total production of
methine and  polymethine dyes and pig-
ments has changed.
  The xanthene dyes  and pigments are
characterized by pure, brilliant hues,  by
fluorescence, and by  a  range of colors
from yellow to violet. In 1972, production
of 530 metric tons for all xanthene dyes
was  reported to the U.S. Tariff Commis-
sion (1974). This represented 0.4% of the
total reported U.S. dye production of 120,
000  metric tons  for that year. The xan-
thene dyes and pigments represented the
ninth largest  structural  class of dyes
based on U.S. production volume. Data  on
U.S.  production by structural class has
not been reported since 1972, so it is not
possible to determine from public sources
whether the relative importance or total
production of  xanthene dyes and  pig-
ments has changed.
  The phthalocyanine dyes and pigments
are brilliant and greens that are stable
with respect to heat and light, acid, and
alkali. They are used in paints, lacquers,
inks, plastics, and rubber. For fiber dyeing,
the  phthalocyanine  pigments can be
made into temporarily soluble dyes that
are subsequently insolubilized on and in
fibers. Soluble phthalocyanine pigments
precursors can be printed on fiber and
cured with heat to form the insoluble
pigments. Solubilizing groups such as
sulfonates can be added to make direct
dyes for paper, cotton, and other textile
fibers. Finally,  additional chemical modi-
fication can add fiber-reactive groups for
dyeing cotton.
  The U.S.  Tariff Commission  (1974)
reported a total 1972  production  of 628
metric tons of phthalocyanine dyes and
6350 metric tons of phthalocyanine pig-
ments. U.S. total production of dyes and
pigments  by  chemical class was not
reported for 1979 (U.S.  International
Trade Commission, 1980), but data from
the  Organic Dyes and Pigments Data
Base prepared  by SRI International
(USEPA, 1984) shows  a total dye produc-
tion of greater than 491 metric tons and a
total pigment production of greater than
8198 metric tons. Thus, pigment produc-
tion grewsubstantially(29% minimum) in
the seven-year period. If phthalocyanine
dye  production had grown  as much, it
would have been 810 metric tons, which
would mean that production of phthalo-
cyanine dyes  would have increased  by
182  metric tons from 1972 to 1979.
  Sulfur dyes  have been produced com-
mercially  for  more than 100 years.  In
spite of  this long history and unlike most
dyes of other classes that  are  clearly
defined compounds of known structure,
the sulfur dyes are, with few exceptions,
mixtures of variable and unknown compo-
sition. There is disagreement as to what
defines  a sulfur dye. The early sulfur dyes
formed a chemical class in that they were
prepared from sulfurization  or "thiona-
tion" of relatively  simple intermediates
with either sulfur or sodium polysulfide.
They also formed a dyeing class in that, as
water-insoluble  substances, they were
brought into soluble form for dyeing by
treatment with a hot solution containing
alkali and sodium sulfide. However, some
newer dyes synthesized by a thionation
procedure but dyed  from an  alkaline
dithionate vat (sodium hydrosulfitevat) in

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the manner of vat dyes were introduced.
Some argued that "sulfur dyes are best
defined as those dyes which are applied
in a reduced state from solutions contain-
ing sodium sulfide, hydrosulfide, or poly-
sulfide and which are subsequently oxi-
dized on  the  fiber" (Orton, 1963). This
definition precluded  dyes made by  a
thionation procedure that were applied as
vat dyes. However, in the listing of dyes by
classes in the Colour Index (1980),  the
"sulfurized vat dyes" are included in the
sulfur dye chemical class. Therefore, we
included these dyes in this study.
  The total production volume of sulfur
dyes is not known. In the mid-1960s, the
U.S. production of sulfur dyes  ranged
from 8100 to 9100 metric tons per year,
representing  7% to  8% of  total dye
production(U.S. Tariff Commission, 1965,
1967,  and 1968). The  importance  of
sulfur dyes as a commercial class has
declined (Allen, 1971), although they are
still in demand because of their moder-
ately good properties and low cost.


Summary and Conclusions
  In this  preliminary study of dyes and
pigments, several waste streams were
identified that might contain  hazardous
materials:

• Discarded shipping containers. These
   would be paper bags and fiber drums
   used to transport dye and pigment
   intermediates and would  contain  a
   residual amount of intermediate when
   emptied.
• Solid residues from process synthesis,
   distillation, and filtration. These would
   contain unreacted dye intermediates,
   reagents, and reaction by-products.
• Filter cake  from clarifying operations.
   This cake could contain dye, unreacted
   intermediates,  solvent,  by-products
   formed in the synthesis of  intermedi-
   ates,  metallic catalysts, and other
   impurities.
• Still bottoms in  the production  of
   anthraquinone dyes  and  pigments
   from the recovery operations of many
   of the organic solvents—chloroben-
   zene,  o-dichlorobenzene,  acetone,
   xylene, nitrobenzene, isobutyl alcohol,
   naphthalene, phenol, and pyridine.
• Gaseous emissions that may contain
   nitrogen oxides (stilbene dye manufac-
   ture); phosgene, formaldehyde, nitro-
   gen oxides and arylamines (diphenyl-
   methane and triarylmethane dye and
   pigment manufacture); ethylene oxide,
   formamide, arylamines and chlorina-
   ted aromatic solvents (phthalocyanine
   dye and pigment manufacture); and
   hydrogen sulfide (sulfur dye manufac-
   ture).
• Process wastewater that may contain
   mother liquor from filtering operations.
   This is probably the  major source of
   discharge of organic chemicals from
   most stilbene plants. In phthalocyanine
   dye and pigment manufacture, organic
   materials and heavy metals from the
   various synthesis steps and PCBs may
   be present. Brines in the manufacture
   of sulfur dyes contain inorganic sulfur
   compounds and some organic com-
   pounds. Process wastewater from the
   manufacture of diphenylmethane and
   triarylmethane  dyes  and pigments
   may contain organic materials and
   heavy  metals.
• Wastewater  treatment solids. The
   evidence suggests that the solids will
   be contaminated with low levels of all
   of the  dye and pigment intermediates
   as well  as the dyes and pigments
   themselves and some reaction  by-
   products. If these solids are placed in a
   landfill, intermediates may be released
   as a result of reduction of the  azo
   linkages under the  anaerobic condi-
   tions prevailing in the landfill.
• Baghouse fines. The fines are gener-
   ated during the drying, standardizing,
   and packaging of the dyes and pig-
   ments. The fines will be principally the
   dyes and pigments and  inert salts.
   Anaerobic conditions in a disposal site
   could  cause intermediates to be re-
   leased from these fines.
  Information on the producers of dyes
and  pigments and  production volume
information  were analyzed  to choose
representative production facilities where
a sampling program  might be conducted
to determine  the composition of the
waste emissions. The following compa-
nies are recommended by dye class:

Azo dyes and pigments
(exluding benzidine)
  American Color and Chemical Corp.
  American Cyanamid Co.
  Atlantic  Chemical Corp.
  E. I. Du Pont de Nemours & Co., Inc.
  Harshaw Chemical Co.
  Toms River Chemical Corp.

Azo dyes and pigments
(benzidine and its congeners)
  Fabricolor, Inc.
  Sterling Drug, Inc.,
   Hilton Davis Chemical Co. Div.
  Sun Chemical Corp.
  Atlantic Chemical Corp.
  Crompton & Knowles Corp.
  Toms River Chemical Corp.

Stilbene dyes and fluorescent
brightening agents
  American Color & Chemical Corp.
  American Cyanamid Co.
  Ciba-Geigy Corp.
  Toms River Chemical Corp.
  Mobay Chemical Corp., Dyestuff Div;

Anthraquinone dyes and pigments
  Toms River Chemical Corp.
  American Color & Chemical Corp.
  American Cyanamid Co.
  BASF Wyandotte Corp.
  Eastman Kodak Co.,
   Tennessee Eastman Div.
  Mobay Chemical Corp.,
   Dyes & Chemical Div., Lowell, NC
  Crompton & Knowles Corp.,
   Dyes & Chemical Div., Lowell NC

Diphenyl methane and triarylmethane
dyes and pigments
  American Cyanamid Co.
  Dye Specialties, Inc.
  H. Kohnstamm & Co., Inc.
  Max Marx Color & Chemical Co.
  Sterling Drug, Inc.,
   Hilton Davis Chemical Co. Div.

Methine and polymethine
dyes and pigments
  Atlantic Chemical Corp.
  Mobay Chemical Corp.
  BASF Wyandotte Corp.
  Toms River Chemical Corp.

Xanthene dyes and pigments
  Max Marx Color and Chemical Co.
  Sun Chemical Corp.
  Sterling Drug Inc.,
   Hilton Davis Chemical Co. Div.

Phthalocyanine dyes and pigments
  ICI Americas Inc.,
   Chemical Specialties Co.
  American Hoechst Corp.,
   Industrial Chemicals Div.
3

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  Sun Chemical Corp.
  Ciba-Geigy Corp.
  American Cyanamid Co.
   (Marietta, OH, plant)
  Toms River Chemical Corp.

Sulfur dyes
  Martin-Marietta Corp., Sodyeco Div.
  American Cyanamid Co.

Process Chemistry
  A  discussion  of  the process  steps
required to synthesize dyes and pigments
will  aid  in formulating the emission
estimates and is  found in the reports on
each major dye class.


Sources of Waste Discharges
During  Dye and  Pigment
Manufacturing
  The wide  range of dye and  pigment
production processes  and the specific
plant characteristics and process control
capabilities  make estimating  material
losses during dye manufacture a difficult
task.  In  general, the  most significant
material losses are intermediates that do
not react and by-products such as incom-
plete dye or pigment  molecules.  The
intermediates and by-products  from the
dye manufacture are present either in the
product or in  the solid waste streams
regulated under RCRA, which include
wastewater, solid residue, and the vapor
and dust emissions. The material in the
wastewater  is discharged in the plant
effluent and some is discharged on any
wastewater treatment solids.
  The sources of wastes from dye manu-
facture identified in Figure 1  are sum-
marized below:

 • Material handling—Airemissionsfrom
   raw material dusting and volatilization,
   solid residue on shipping containers,
   and process wastewaters from  equip-
   ment washdown.
 • Dye syntheses—Air emissions from
   the volatlization of intermediates and
   by-products from reaction vessels,
   solid residuals from distillation resi-
   dues  and spills,  and process waste-
   waters from equipment washdown.
 • Product and intermediate  filtration—
   Air emissions from  unreacted inter-
   mediate and by-product volatilization
   during material  handling, solid resi-
   dues from spills,  and process waste-
   water from equipment washdown.  A
   significant additional source of process
  wastewater is the mother liquor when
  aqueous processes are used.
• Drying—Air emissions from volatiliza-
  tion of by-products and unreacted
  intermediates in the drying oven, and
  solid residues from spills and dusting
  of the product dye.
• Grinding,  blending, standardization,
  and packaging—Solid residues from
  dusts produced by the grinding opera-
  tions that  may  be either in the air
  streams from vent systems  designed
  to prevent the material from entering
  the workplace environment or as a
  solid residue from spills.
• Air pollution control—Solid residues
  from baghouses or scrubbers  collecting
  fine dusts  and process wastewaters
  from scrubbers.

  Each dye producer may have a different
wastewater  treatment system. Some
process wastewaters  are discharged
directly to sewers  and  thus to publicly
owned treatment works. Some waste-
waters are sealed  in  drums, which are
placed in a landfill. Some producers have
on-site wastewater treatment plants. All
these treatment plants will be site-specific
designs with site-specific behavior. Sev-
eral examples of on-site treatment facil-
ities at dye production sites are discussed
to indicate the type of treatment often
used and  its effectiveness.

References
Allen, R.  L M. 1971. Color Chemistry.
  Appleton-Century-Crofts, New York.
Orton, D. G. 1963.  Sulfur Dyes. In: Kirk-
  Othmer Encyclopedia of ChemicalTech-
  nology,  Interscience, New  York,  pp.
  424-441.
The  Society  of Dyers and Colouritsts.
  1980. Colour Index. Lund Humphries
  Printers, London, England, Volumes 1 -
  3, Third Edition,  1975; Additions and
  Amendments Numbers 13-36, October
  1974-July  1980.
U.S. Environmental Protection Agency.
  The Organic Dyes and Pigments Data
  Base. EPA-600/1-84-032, Cincinnati,
  Ohio, 1984.
U.S. International  Trade Commission.
  1980. Synthetic Organic Chemicals,
  U.S. Production and Sales, 1979. USITC
  Publication 1099.
U.S. Tariff Commission. 1965.  Synthetic
  Organic Chemicals, U.S. Production and
  Sales, 1964. TC Publication  167, U.S.
  Government Printing Office,  Washing-
  ton, DC.
U.S. Tariff Commission. 1967.  Synthetic
  Organic Chemicals, U.S. Production and
  Sales, 1965. TC Publication 106, U.S.
  Government Printing Office, Washing-
  ton, DC.
U.S. Tariff Commission. 1968. Synthetic
  Organic Chemicals, U.S. Production and
  Sales, 1965. TC Publication 248, U.S.
  Government Printing Office, Washing-
  ton, DC.
U.S. Tariff Commission. 1974. Synthetic
  Organic Chemicals, U.S. Production and
  Sales, 1972. TC Publication 681, U.S.
  Government Printing Office, Washing-
  ton, DC.

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                                                                                            Air Pollution
                                                                                              Control
                                                                                                         Solid Waste
                                                                                               Wastewater
                                                                                              Grinding,
                                                                                              Blending
                                                                                           Standardization.
                                                                                                and
                                                                                              Packaging
                                                                                    Product
                                                                                               Solid Waste
   Process
 Wastewater
 Process
Wastewater
  Process
Wastewater
                                            Mother Liquor

Figure 1.    Production operations that are sources of waste emissions in dye and pigment manufacture.
  Process
Wastewater
  D. C. Bomberger, R. L Boughton, and J. E. Gwinn are with SRI International,
    Menlo Park, CA 94025.
  M. J. Stutsman is the EPA Project Officer (see below).
  The complete report consists of nine volumes, entitled "Wastes from Manufacture
    of Dyes and Pigments:" (Set Order No. PB 84-200 864; Cost: $79.50)
      "Volume I.Azo Dyes and Pigments (Benzidine and Its Congeners Subsector,"
       (Order No. PB 84-200 872; Cost: $ 11.50)
      "Volume 2. Azo Dyes and Pigments (Excluding Benzidine and Its Congeners,"
       (Order No. PB 84-200 880; Cost: $ 19.00)
      "Volume 3. Stilbene Dyes and Fluorescent Brightening Agents," (Order No.
       PB 84-200 898; Cost: $8.50)
      "Volume 4. Anthraquinone Dyes and Pigments," (Order No. PB 84-200 906;
       Cost:$11.5O)
      "Volume 5. Diphenylmethane  and Triarylmethane Dyes and Pigments,"
       (Order No. PB 84-200 914; Cost: $8.50)
      "Volume 6. Methine and Polymethine Dyes and Pigments," (Order No. PB
       84-200 922; Cost: $8.50)
      "Volume 7. Xanthene Dyes and Pigments," (Order No. PB 84-200 930; Cost:
       $8.50)
      "Volume 8. Phthalocyanine Dyes and Pigments," (Order No. PB 84-200 948;
       Cost: $8.50)
      "Volume 9. Sulfur Dyes," (Order No. PB 84-200 955; Cost: $8.50)
  The above reports will be available only from: (cost subject to change)
          National Technical Information Service
          5285 Port Royal Road
          Springfield, VA 22161
          Telephone: 703-487-4650
  The EPA Project Officer can be contacted at:
          Industrial Environmental Research Laboratory
          U.S. Environmental Protection Agency
          Cincinnati, OH 45268
                                                                  •&U. S. GOVERNMENT PRINTING OFFICE: 1984/759-102/10691

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United States
Environmental Protection
Agency
                                      Center for Environmental Research
                                      Information
                                      Cincinnati OH 45268
Official Business
Penalty for Private Use $300
                                            a*(i  "   ,
                                            CrUf»t>vj

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